The Upstream Tunnel for Yellow River Crossing Project Completed

Builders Celebrate Tunnel Completion

On June 22, the inauguration ceremony of the upstream tunnel for Yellow River Crossing Project of Middle Line of South-north Water Transfer Project was held at the exit of Mangshan Tunnel in suburban Zhengzhou.

At 10:25 am, a shield machine was started by Zhang Jiyao, director of the office of State Council for South-north Water Transfer Project and Liu Mancang, vice governor of Henan and it reached the tunnel exit in five minutes. Upstream tunnel excavation, jointly undertaken by CGGC and China Railway Tunnel Group, was completed successfully, marking an important milestone for the project.

Yellow River crossing is of great importance for the middle line of the South-north Water Transfer Project. It involves the longest blind heading in the country which was done by a state-of-the-art slurry balanced shield machine without replacing the cutter. It is hailed by the industry as a brilliant feat of engineering due to its application of the world s most sophisticated technologies to meet the numerous challenges.

CGGC conquered a series of technical challenges since the river crossing was launched on September 27, 2005, To name just a few, hydraulic dual-wheel milling grooves were used for the 76.6-meter-deep underground continuous wall in shaft work, and a double-high-pressure triple-tube spun jet method was adopted for 55-meter-deep foundation stabilization.

The shield machine was assembled in the north bank shaft in June 2007. Having started successfully and experienced 500 chamber-time cutter replacements under high pressure, it tunneled under the river for a distance of 3,450 meters until it reached the south bank shaft by December 22, 2009 and received maintenance there. And the completion of the 750-meter Mangshan tunnel on June 22, 2010 represents a decisive success in the river-crossing part of the project.